Grinding machine



Y May J.- SODERBERG GRINDING MACHINE Fired ont. 11. 1922 4snets-sheet 1 May 115, 1926l 1,583,807

' J. SODERBERG GRXNDING MACHINE 4 sneetssneet '2 Filed QCC. l1, 1922 May 11v 1926.

1 A 1,583,801 J. SODERBERG v GRINDING MACHINE md om. 11, 1922 4 snee1s-sheet s FGa.

11W' l?? e 1,583.807 J. SODERBERG f I QRINDING MACHINE l i Filed oct. 11, 1922 s sheets-s119614 Patented May 111, 19.26'.`

UNITED STATES ,PATENT orties.,

JACOBv SODEBBERG, OF PITTSBURGH, PENISYLVANIA, ASSIGNOR T PITTSBURGH. .'.PLATE GLASS COMPANY, A CORPORATIQN 0F PENNSYLVANIA.

GRINDING MACHINE.

Application led October 11,l 1922. i Serial No. 593,?60.

"The invention `relates to grinding machines of the type in which a continuous sheet or ribbon of glass or a series of sheets are carried beneath a series of grinding or smoothing runners, each of which erforms a surfacing function upon theg ass,

suitableabrasives, such as, Sandor emery, being supplied withv Water as is common 1n sheet glass grinding operation. In the case n of a continuous ribbon of glass, such ribbon must of necessity be carried in a straight7 line beneath the grinders, but in lthe case of a series of sheets, the movement may. be either in a straight line'or onan are having a relatively large radius of curvature as would be the case in carrying the sheets around a circle beneath the series of grinders. The principal object of the invention is the provision of an arrangement of grinders of such a character, (l) that the grinding or reducing enect upon is made as nearly uniform as may be across the width of the sheet, 2) that-the grinders themselves will Wear uniformly, (3) that the grinders will grind at a more or less uniform speed throughout their grinding areas so that a maximum degree of grinding eifect per unit of time (for the Weight of grinders and speed or rotation thereof) may be secured.' One embodimentpof the invention is4 illustrated in the accompanying drawings wherein: y

Flgurel 1s a diagrammatic plan View showing the arrangement of the runners with respect to a series of sheets of glass adapted to be carried longitudinally beneath the runners; Fig. 2 is a plan View of a short section of the apparatus; Fig. 3 is aside elevation of the apparatus of Fig. l; Fig. l is an end elevation of such apparatus and Fig. 5 is an enlarged vertical section through the center of one of the runners.

As indicated. in Fig. l, the glass to be ground consists of a. series `of sheets ofglas's l, 2, 3, 4, etc. preferably mounted upon a vseries of .trucks or tables arranged for longitudinal movement beneath a series of runners 5, 6,7, 8, c'te., but it will be understood that the invention is 'applicable Where vthe glass is in one continuous ribbon instead of a plurality of sections. The nuInber of runners employed Will depend upon Varying conditions, among which is the the glass surface -of the series of sheets of speed of movement of the glass underneath the runners. If the speed of movement of the glass ranges-from two to three feet per minute, the number of runners required will range ordinarily from l5 to 25, depending upon the roughness of the glass surface t0 be smoothed. The glass is ground by the use of abrasive and Water, the abrasive preferably used for the coarser grinding being sand and for the final smoothing operation being emery. The grade of sandV used with thevarious runners is progressively finer from the first ruimer Ato the last, and similarly several grades of emery are preferably used with the last runners for giving the necessary smoothing effect preliminary to the polishing of the glass Which vvill also preferably be eifected by continuindicated at 9, 10, 11 and 12 and the centers 0r axes of rotation of the runners are placed off the center line A glass, the alternate ocated With their center with respect to runners 5, 7, etc. being centers on the line B, the other alternate runners 6, 8, etc. are located on ,the line C'. The cutting-out of the centers of the runners increases the speed of the surfacing action effected bythe runners. The cutting eii'ect ofthe runners'at any point is `dependent upon the speed .of movement relative to the glass, and this speed of move? ment decreases from the outside 'of the run-- ner to the center, so that the cutting action is less at thecenter, as nell as the lwear upon the ruimer.` rlhe tendency is, therefore, for the runners to Wear away at their outer portions, leaving the center high.v is, as the grinding progresses, to Wear the outer portions of the runners so that they are out lof contact with the glass and, if the glass While the'centers of The eifect.

past the side edges 39 i theretore becomes 3*-5 lustrated tends to produce this eilect.

'm cut which extend only at right 35 tifat the speed ot' t5 center which the runners are 59 it works its way to the freater so that these t5 glass at any particular point depends upon the crossing at this point of the lines ot cut, The cutting action is much more rapid it the lines of cut crisscross at varying angles than where they are in the same direction. lt

desirable, that this crisscross cutting eiiect be extended uniformly over the entire area of the sheet passing beneath the series of runners. The placing of the runners ott center in the manner ilillustrate, if the centers of the runners all coincide with the center line of the series of ribbons, the band of glass extending along this line A on eachsheet would have lines ot' angles to the would be no dcrisscross cutting at. this point. On the other hand, the glass lying on cach side of such line would receive cuts at different angles, for inline A, so that there 3f-5 stance, along the line the glass will receive a plurality ot cuts ot varying angular direction, as indicated by the arrows y. By placing the centers of the runners oil' center, the glass along the line A will be given the varyil@ ing crisscross cuts to which the rest ot the surface of the glass is exposed, as indicated by the arrows a. This expedient, therefore, renders the grinding action much more uniform throughout the width of the glass, so cutting is increased and the wear upon the runners made more uniform, and the surface orsmoothsecured upon the dass rendered much more uniform, thus fa'- O. ciiitating the subsequent polishing operation.

@ This condition or" uniform cutting due to the crisscross cuts is adpisted so as to give a satisfactory grinding action by the extent which the runners are made to overhang the glass at its edges and by the distance oit placed.

.As the abrasive' is supplied through the centers of the runners, t e tendency is to cut faster near the center due to the iact that the abrasive is coarser and sharper before outer portions ot the runners, but on the other hand the cutting eect of the runner is normally greater at its outer portions due to thc tact that its speed oit movement relativeto the glass is two conditions tend to balance cach other and give more or less uniform wearing action upon the runner throughout its grinding tace. If, however, the runner wears more or less at its outer portion as compared with its inner portion, a definite curvature upon the grinding face will soon be established and remain constant, since the wearing eii'ect also` depends upon the pressure between the runner and the fr, i @t glass and, any portion o the runner is .runner 7 as indicated meegaat mounted over a series of tables or trucks 13, '14 and l5 carried by the railsl, such tables y having their ends overlapping as indicated at 17 (Fig, in order to provide a continuous support for the glass. The series of tables'may be moved along the track by any drive means desired, such as a) cableor gearing or a locomotive (not shown) `which pushes or pulls at one end of the series of cars. The glass isheld upon the table in any desired manner, either by the use of plaster, as is common in the art, or by suction or by mechanical means at the edges of the sheets for preventing their lateral nuoveinent upon the tables.

rlhe runners are supported upon a suitable framework inade up of the channels 18, 19, 20 and 2l in connection with the cross channels 22 and 23 (Figs. 3 and il) so that a description of one runner and its drive mechanism will be' suiicient. The motor drives a countershatt 25 carried by suitable bearings on the framework through the intermediary of the belt 26, the pulley 26l and the bevel gears 27 and 28. countershaft 25 is provided with a Apinion 29 which drives the spur gear 30 carried by the drive shaft 3l of the runner. This drive shaft is mounted 4in the bearings 32 and carried by the vframeworkv and is flexibly.. connected at its lower end with the in detail in Fig. 5, the purpose being to permit the runner to rock with respect to the shaft 3l, and so adjust itself to the surace-ot the glass. thus giving a more uniform cutting action throughout its area and decreasing the danger of breakage incident to localized pressure upon the glass. The runner itself comprises acasting 33 or castings bolted together, bearing on its lower 'face the planking 34 which carries the cast iron runner bars 35, such runner bars being preferably of the ordinary type having their faces divided into the usual diamond or other similar sectional form. Mounted upon the top ot-the ruimer is a pair ot bearings 36 which receive the bearing ends 37 ot 4the ring member 38. Mounted in the ring member 'for rocking movement is the collar B9', such collar member being pivoted upon lthe ring 38 byA means ot stub shafts 4l() which .are carried by the ring 38 and project into suitable bosses on the sides The- ,itself to the surface-of of the collar 39. In order to limit the rocking movement around the stub shafts 40, the stop members'41 Aare provided in opposition to the shoulders 42 on the ring 38. The shaft 31 is keyed to the collar 39, as indicated at 43. vThe foregoing arrangement permits the runner to rock in any direction with respect to the shaft 31 and so adjust the glass.

Mounted upon the top of the collar 39 is a hopper 44 provided with outlet pipes 45 leading downward through the collar 39 and discharging into the space 11 at the center of the runner. This is toprovide for the feed of the abrasive through the center or' the runner, the hopper being supplied from a pipe 45 leading from a suitable source of supply.

In order-to regulate the pressure of the runner upon the lass, the lever 46 (Fig. 4) is employed, suo lever being fulcr'umed upon the member 47 carried by the framework and having its vend 48 forked and tting beneath the thrust lnember 49 secured to the drivevshaft 31. At the outer end ofthe lever is a rod 50 provided with a fixed aging. the

head 51 and a movable head 52 eng upper side of the lever with anv4 interposed spring 53. The tension ofthe spring is regulated by means of the hand wheel 54 which is threaded onto the rod 50 and swiveled at the end of the frame channel 23. By

.this device the pressure of the runner upon the lass is regulated and the dan er of any brea age ofthe glass on its 'downwar movement after a sudden upward movemen is reduced since thespring 53 cushions this downward movement.

lThe operation of the machine will be apparent from the foregoing description; The

glass is placed upon the tables, preferably in a series of sections and the tables car' riedslowly beneath the series of runners. The coarsest sand .is supplied to the first runner, while liner and finer grades are su plied to the succeeding runners until. t e dass is relatively smooth, at which time the eeding of emery is be un, as many grades of emery or other ine a rasive being used as edges of the sheet is necessary -to complete gitudmal movement and carrying the glass sheet to be surfaced,A a plurality ofho'rizontal grindin discs, having their centers open, arrange in two sets or series along the table with their axes of rotation off center with respect to the longitudinal center line -of the table and of such diameter that each disc extends out past both of the side a substantial distance, one set or series of said discs having their axes to one side of such centerline, and the other set or series having their'axes on the other side of such center. line, but all of said axes being located inward from the side edges of the glass sheet, and means for rotating the' discs. y l

2. .A grinding machine ffor sheet glass comprising a bed or table mounted for longitudinal movement and carrying the glass sheet to be surfaced, a plurality of horizor tal grinding discs, arranged in two sets or series along the table with their axes of rotation ofi' lcenter with res t to the longitudinal center line of the tab e and of such diameter thatbeach disc extends out past both of the side edges of 50 polhaving their centers open, I

the sheet a substantial distance, `one set4 or series of said discs having their axes to one side of such center line, and the other set or series having their axes on the other side of Isuch center line but all of said axes being, located inward from the side, edges of the glass sheet, and means for rotatin the discs, the two sets or'series of discs eing intersprersed so that the discs of one set alternate with those of the other set or series.

In testimony whereof, I have hereunto subscribed my 1922. 1

JACOB sonnn'nne.

name this 26th day of Sept., 

